The 4 Seasons Posted January 24, 2016 Share Posted January 24, 2016 Before it fades, what's the Memento tattoo we're giving this blizzard regarding guidance? My impression was that many pro forecasters (and myself and many here) were led astray by the Euro / RGEM and skepticism of the NAM, but in the end the NAM led the way and crushed other guidance with the significantly more north track and prodigious qpf especially in NYC, as well as the easternmost of the dual-low kicking back a CCB for us. Do we mark this one, like Juno Jan 29 2015, as another really impactful Euro subpar performance within 24 hours? And a rare but really significant NAM coop? I would say that the NAM while being correct for NYC NNJ LI and South Coast of SNE, was way too far north with the heaviest axis of precipitation. It did correct downward on later runs but those runs where it had heavy snow up to the VT boarder and ALY were as wrong as the Euro RGEM were south. Then it corrected and those runs were closer to reality than any other model had at the time. So all in all I would say the NAM was the least wrong with placement of the precip shield and intensity of QPF. Just my opinion others can certainly weigh in Link to comment Share on other sites More sharing options...
Organizing Low Posted January 24, 2016 Share Posted January 24, 2016 Before it fades, what's the Memento tattoo we're giving this blizzard regarding guidance? My impression was that many pro forecasters (and myself and many here) were led astray by the Euro / RGEM and skepticism of the NAM, but in the end the NAM led the way and crushed other guidance with the significantly more north track and prodigious qpf especially in NYC, as well as the easternmost of the dual-low kicking back a CCB for us. Do we mark this one, like Juno Jan 29 2015, as another really impactful Euro subpar performance within 24 hours? And a rare but really significant NAM coop? I didn't see every model run over the past week, but as an outside impartial observer its definitely a NAM coup, any way you slice it sure it came way too far north at times but then corrected, but imagine if the NAM/SREFs and its amped subset did not exist, there would have been less than 24 hours lead time. the NAM kept folks guessing that it could have a bigger impact further N, and in a storm like this, that kept everyone on their toes and that turned out to be important in terms of preparation. personally, I am shocked. LOL Link to comment Share on other sites More sharing options...
Organizing Low Posted January 24, 2016 Share Posted January 24, 2016 btw ive been trying to get into this subforum all evening to see what was going on around here, and the internet keeps locking up strangely enough no issues with getting into the NYC and MA subforums....I think they leveraged our bandwidth Link to comment Share on other sites More sharing options...
eduggs Posted January 24, 2016 Share Posted January 24, 2016 I didn't see every model run over the past week, but as an outside impartial observer its definitely a NAM coup, any way you slice it sure it came way too far north at times but then corrected, but imagine if the NAM/SREFs and its amped subset did not exist, there would have been less than 24 hours lead time. the NAM kept folks guessing that it could have a bigger impact further N, and in a storm like this, that kept everyone on their toes and that turned out to be important in terms of preparation. personally, I am shocked. LOL The SREF mean was WAY too far north for run after run in the 24-48 hr range. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 24, 2016 Share Posted January 24, 2016 Southern RI always dryslots. Is there any logic to this? Maybe just coincidence or selective memory through recent occurrences...well after 12-15 inches but read back a couple of pages Link to comment Share on other sites More sharing options...
TauntonBlizzard2013 Posted January 24, 2016 Share Posted January 24, 2016 Nice winter scene out there..... Even some blowing and drifting. It isn't 30 inches..... But it'll do Link to comment Share on other sites More sharing options...
wxsniss Posted January 24, 2016 Share Posted January 24, 2016 There was some discussion earlier that I wasn't part of about perhaps the reason for the NAM doing well...and I agree with the theory. In this storm, the synoptics were not in doubt...it was a massive ULL with nothing overly complicated like multiple streams phasing or multiple vortmaxes phasing which we sometimes see in coastal storms. So this was less chance for the NAM to screw up synoptic aspects of the forecast where it has a decided disadvantage against models like the Euro. Given just how intensely moisture-laden and convective the system was as it exited the southeast, this is where the NAM could shine without "worrying" if the synoptics were wrong since things were already really set in stone there....it could model the latent heat much better than the Euro and other models. That mattered in a storm so big and so convective with the really monster ULL. It pumped the heights up more than other guidance and it was correct (for the most part). I certainly wouldn't go around trusting the NAM in future forecasts, but it's an interesting case study this time. We did mention earlier that it tends to score coups occasionally in very convective systems. 1/12/11 sort of matched that...though there wasn't nearly the spread in guidance in that system as this one. That's a fantastic theory, thanks. Agree this would be a fantastic case study because it also wasn't just a fluke run, it was multiple consistent runs in a row by the NAM vs. Euro. And it was hugely impactful. NAM kept mets covering NYC / far northwestern Philly burbs / south coast SNE appropriately on edge, and even still there was significant catching up with forecasts. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 24, 2016 Share Posted January 24, 2016 Snowing again after snowing under a full moon. Full moon goon. This week in Jan certainly has a historical agenda. Link to comment Share on other sites More sharing options...
NorEastermass128 Posted January 24, 2016 Share Posted January 24, 2016 Jesus, you have 4" down the west end of Woburn? Not event 10 mi se of me....1" Tough break for you. I just BARELY made it into the show. Amazing how it went from nothing to a few/several inches. Link to comment Share on other sites More sharing options...
Cold Miser Posted January 24, 2016 Share Posted January 24, 2016 7" here in Brooklyn, CT thus far (as of 11:45). Still snowing. Link to comment Share on other sites More sharing options...
wxsniss Posted January 24, 2016 Share Posted January 24, 2016 I didn't see every model run over the past week, but as an outside impartial observer its definitely a NAM coup, any way you slice it sure it came way too far north at times but then corrected, but imagine if the NAM/SREFs and its amped subset did not exist, there would have been less than 24 hours lead time. the NAM kept folks guessing that it could have a bigger impact further N, and in a storm like this, that kept everyone on their toes and that turned out to be important in terms of preparation. personally, I am shocked. LOL That's a great perspective, I agree. Imagine the shock if NYC public went in expecting a mundane 3-6" or whatever the Euro was showing 0z Friday, 24 hours of go-time. Yeah those Euro runs really threw off many. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 24, 2016 Share Posted January 24, 2016 7" here in Brooklyn, CT thus far (as of 11:45). Still snowing.beautiful night just got back in. The full moon was out and it was literally ripping for a couple of minutes. Bright moonshine lit snowscape, 20 degrees, drifting snow, and snow falling, whats not to.like. Link to comment Share on other sites More sharing options...
Ginx snewx Posted January 24, 2016 Share Posted January 24, 2016 That's a great perspective, I agree. Imagine the shock if NYC public went in expecting a mundane 3-6" or whatever the Euro was showing 0z Friday, 24 hours of go-time. Yeah those Euro runs really threw off many. the one spurious Euro run was weird. Seems to do that. I think having the extra soundings in the USA mesos really helped fine tune them the last 36 hrs. 4 k Nam being north of the OP was a bell in my head. Link to comment Share on other sites More sharing options...
TauntonBlizzard2013 Posted January 24, 2016 Share Posted January 24, 2016 Coming down pretty good now must be one last gasp Link to comment Share on other sites More sharing options...
wxsniss Posted January 24, 2016 Share Posted January 24, 2016 the one spurious Euro run was weird. Seems to do that. I think having the extra soundings in the USA mesos really helped fine tune them the last 36 hrs. 4 k Nam being north of the OP was a bell in my head. Does Euro not get extra USA soundings that the mesos have? Yeah 4k Nam for sure raising alarms. The SREFs verbatim we rightfully tossed but having such excessively north solutions (high qpf to Syracuse in some runs?) was also an alarm. RGEM was also a little behind until Friday... Euro / RGEM combo seems more dependable with Miller B's? Or as Will said, more dependable with complex synoptics. Link to comment Share on other sites More sharing options...
Cold Miser Posted January 24, 2016 Share Posted January 24, 2016 beautiful night just got back in. The full moon was out and it was literally ripping for a couple of minutes. Bright moonshine lit snowscape, 20 degrees, drifting snow, and snow falling, whats not to.like. Did not see the moon, but visibility is good, and it's bright through the clouds with snow still falling. No 40" like west VA, and no 24"+ like DC metro, but considering how crappy it's been this winter, and how the past few days our area was foretasted to get much less by some, this is pretty good. I only hope we do get another shot at a monster snow storm before the season winds down. Link to comment Share on other sites More sharing options...
Organizing Low Posted January 24, 2016 Share Posted January 24, 2016 The SREF mean was WAY too far north for run after run in the 24-48 hr range. you're right, the amped SREFs were far too north even late in the game, so yes my mistake. but the folks down in NYC were clinging to the NAM/SREFs for dear life. in the end it was all about the NAM. Will's explanation is a great one, and allows us to go to bed with at least some peace of mind, lol Link to comment Share on other sites More sharing options...
CT Rain Posted January 24, 2016 Share Posted January 24, 2016 FYI Link to comment Share on other sites More sharing options...
TauntonBlizzard2013 Posted January 24, 2016 Share Posted January 24, 2016 New York just shy of the all time record Link to comment Share on other sites More sharing options...
Morch Madness Posted January 24, 2016 Share Posted January 24, 2016 FYI Yeah a lot of people championing the NAM and SREFs, I disagree. Maybe they did well around NYC, but they certainly were not accurate here, or else most of SNE would have over a foot of snow. Link to comment Share on other sites More sharing options...
MegaMike Posted January 24, 2016 Share Posted January 24, 2016 well after 12-15 inches but read back a couple of pages I only see four towns in southern RI with 9+ inches of snow, Regardless, I should've been more specific. I mean Providence, northern Washington, and northern Newport counties. Found it from Arnold214: "i've seen this Rhode Island snow hole pattern a few times in the last several years. In addition to what you say, I think once you get a certain wind direction with a long fetch you get a standing wave pattern that develops. Rhode Island just seems to be in the subsidence portion of that on a few occasions. Sometimes I've even seen it modeled pretty well." Link to comment Share on other sites More sharing options...
CT Rain Posted January 24, 2016 Share Posted January 24, 2016 Yeah a lot of people championing the NAM and SREFs, I disagree. Maybe they did well around NYC, but they certainly were not accurate here, or else most of SNE would have over a foot of snow. In retrospect I think the NAM did give some clues. In the areas we knew had good synoptic lift/moisture (I.e. NYC and to some extent south coast) then NAM probably could have been useful for some mesoscale details. Up here, it was pretty clear from the get go it was a garbage solution. Link to comment Share on other sites More sharing options...
Organizing Low Posted January 24, 2016 Share Posted January 24, 2016 New York just shy of the all time record 26.8, wow, what a smack in the face that is! I was there in feb 2006 and while everyone always says it was a suspect 26.9 measurement, I can say it thundered and lightning on and off for 2 hours in midtown/CPK that morning in the midst of a deathband, enough to wake me out of a dead sleep. and then of course I ran outside to enjoy it haha. there was definitely right around 2 feet of snow in central park that afternoon, give or take.... but what a bitter pill......uffff, that's a tough one. Link to comment Share on other sites More sharing options...
ma blizzard Posted January 24, 2016 Share Posted January 24, 2016 3.1" imby in shrewsbury already can see the stars / moon as skies quickly cleared behind the last band of snow Link to comment Share on other sites More sharing options...
ORH_wxman Posted January 24, 2016 Share Posted January 24, 2016 In retrospect I think the NAM did give some clues. In the areas we knew had good synoptic lift/moisture (I.e. NYC and to some extent south coast) then NAM probably could have been useful for some mesoscale details. Up here, it was pretty clear from the get go it was a garbage solution. The northern edge of the precip shield was always suspect...so in that sense, just looking at the QPF in our areas wouldn't tell us that is did better than a model like the Euro. Some of its runs were too amped for sure. But certainly the general idea of huge snows in NYC, NNJ and probably the south coast to a lesser extent was where it scored the coup. Just having the system far more amped than any other guidance for a while. Link to comment Share on other sites More sharing options...
TauntonBlizzard2013 Posted January 24, 2016 Share Posted January 24, 2016 Still snowing pretty good.... Link to comment Share on other sites More sharing options...
Morch Madness Posted January 24, 2016 Share Posted January 24, 2016 Final total at BOS of 6.1". Not bad at all. I'd say it was probably a general 6-8" around the city. Link to comment Share on other sites More sharing options...
jm1220 Posted January 24, 2016 Share Posted January 24, 2016 In retrospect I think the NAM did give some clues. In the areas we knew had good synoptic lift/moisture (I.e. NYC and to some extent south coast) then NAM probably could have been useful for some mesoscale details. Up here, it was pretty clear from the get go it was a garbage solution. I think the NAM did a pretty bang-up job all things considering. Certainly better than the Euro, which caught up to the NAM(!) at the 12z run preceding the 0z run when the NAM was on its own with its massively overdone 1.5" liquid printout all the way to Albany. It still caught a trend first, before normally more useful models, even shorter term models like the RGEM. The GFS was still waffling around NYC at 0z yesterday. It ended up overdone around Boston and I-90, but a 75% NAM, 25% other models blend was taken 24 hours ago, that would have been pretty good. Link to comment Share on other sites More sharing options...
CoastalWx Posted January 24, 2016 Share Posted January 24, 2016 The NAM last night still had 3-4" QPF for NYC area. I agree that because there wasn't complex intricacies of nrn and srn stream phasing, it only had the single ULL to work with. Combine that with Miller A moisture and it almost works to what it is designed to do. But, it was overblown in this area 36 hrs ago when it has 2-3' south of Boston. However, it hinted at big time frontogenesis that I posted a couple of days ago as a red flag and it worked out rather well. This evening in BOS was almost half CF/OES contribution. That part worked out well, even better than I thought. Link to comment Share on other sites More sharing options...
CoastalWx Posted January 24, 2016 Share Posted January 24, 2016 Tough to tell, but about 5 here. Could be more, but it's wind blown. I'll roll with that. Link to comment Share on other sites More sharing options...
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